I have just found this cave on the side of the mountains in the Cobalt Coastlands and there is nothing inside. It seems strange that it is a marked location on the map but inside there is nothing. Not even any writings on the wall of paintings to explain some kinda story or meaning for this place. Does anyone know what the point of it is?
This is something that you may figure out on your own later, I don’t want to spoil it too much here but this cave will become active at some point in the game. If you want to know more, check out the guide for a side quest called the sea’s legend. This is a fairly long quest that you will pick up later on in the game and it will require you to follow some rather cryptic steps that eventually lead you back to this cave.